Linda Jahnke

I am employed by NASA as a research microbiologist and have worked in the Exobiology/Astrobiology programs as a principal investigator for over 20 years. My work focuses on microbial lipid biochemistry of ecologically significant microorganisms. I am interested in the evolution of early microbial ecosystems particularly in relation to the emergence of the cyanobacteria and oxygenic photosynthesis. Studies in my laboratory identify specific lipid biomarkers and determine the effect of carbon isotopic discrimination associated with biosynthesis in support of environmental microbial community analysis and interpretation of EarthÕs ancient organic geochemical record. My work attempts to understand the influence of environmental change on the lipid composition of microorganisms, and potential deposition and preservation in sedimentary and mineralizing environments.

Current projects and interests involve: 1) biomarker analysis of marine cyanobacteria and associated microbial communities; 2) the influence of UV on cyanobacterial diversity and adaptation with emphasis on potential changes to membrane lipid composition and biomarker contribution to organic sediments; and 3) the influence of photorespiration on the carbon isotopic composition of cyanobacterial lipids and potential effects associated with carbon isotope partition within microbial communities.